suggest you start with Dave Ramsey principals ... then move out from there.there is some big huge fallacy  that Real estate is going to let you quit your job and your going to have all this time for the kiddos etc.this will never happen in the short term with rental property.. you build a nice base for retirement in 30 plus years for sure.. but for short term replace your income and have all this free time you need to make transactional income with big hits.. your not going to get their with 200 to 300 a month cash flow on a levered up rental . 

Most folks would do a wonderful job of losing most or all of the principal. 

You will then have a few options with that rent money....you can put it into principal or you can start saving it to purchase yet another property.

It's always 7.9% on your principal no matter how much appreciation you gain, but the S&P 500 compounds. 

Some of the adjustable products, the payment stays the same, but the principal to interest allocation changes to the point where people are only paying interest and are now in a negative amortization where the amount they owe is actually going up.

In the case of the student housing there is no dividends until refi at year 2 then a large portion of principal is returned then divideds after that.

The recovery, if any, of a holder on a Note may be substantially delayed and substantially less than the principal and interest due and to become due on the Note.

On a 250k loan I can knock off about 3 years from a 30yr mortgage and save $14,000 in interest simply by paying my mortgage with my debit card and using the cashback reward as an additional principal payment.  

You are looking at this strictly through the lens of cash flow, which is typically the smallest compared to appreciation and principal pay down. 

@Dan BlaylockWe are coming out with a new product in the next 3-6 months that will be very similar to a partial where investors will have ability to get principal and interest payments.